I just received an offer from ET Energy Partners for minerals I own in the Robert Steel Sy. A-820 & 827 in Leon County. It seems like a weak offer at $500 per net mineral acre and a 17.5% royalty which includes my portion of their costs incurred for gathering, treating, dehydrating, compressing, processing, transporting and delivering production and any costs of marketing or rendering marketable or more valuable the covered minerals. Can anyone tell me an approximate percentage of a royalty payment that these fees end up costing the royalty owner? Thanks!